Use Individuals Chart to monitor the mean of your process when you have continuous data that are individual observations that are not in subgroups. Use this control chart to monitor process stability over time so that you can identify and correct instabilities in a process.
The process variation must be in control before you assess the process center using an individuals chart because the control limits for the individuals chart are calculated using the within-subgroup variation. If the process variation is not stable, then the individuals chart control limits will be questionable and the chart might show a false out-of-control signal. Use a moving range chart to determine whether the process variation is in control.
To create an individuals chart, choose .